Evaluation of Cevya and Omega Alone and in Combination with Rampart for CFR Management in Massachusetts, 2024

Cranberry fruit rot (CFR), associated with a complex of fungal pathogens including Coleophoma empetri, Allantophomopsis cytisporea, Botryosphaeria vaccinii, and Colletotrichum spp., significantly impacts cranberry ( Vaccinium macrocarpon) production in Massachusetts. Symptoms include softening, discoloration, and decay of berries at harvest. This trial evaluated the efficacy of Cevya (mefentrifluconazole, Fungicide Resistance Action Committee [FRAC] 3) and Omega (fluazinam, FRAC 29), applied alone or in combination with Rampart (phosphonates, FRAC 33), for CFR management. Treatments were compared against a nonsprayed control and a grower standard program composed of QuadrisTop (azoxystrobin + difenoconazole, FRAC 11 + 3) applied at early bloom (EB), Manzate Max (mancozeb, FRAC M03) applied at mid bloom (MB), and Proline (prothioconazole, FRAC 3) applied at late bloom (LB).The study was conducted in 2024 on cranberry cultivar ‘Stevens’ at the University of Massachusetts–Amherst (UMass) Cranberry Station. Several treatments, especially Cevya + Rampart significantly reduced CFR and improved yield on par with the grower standard. These results support the potential of reduced-risk fungicide programs in cranberry production.